Electrical contact materials, also known as materials used for electrical contacts or electrical conductor, contacts or connectors, are an important component found in electrical switches, such as high to low voltage electric switches. They are in charge of connecting or insulating the circuit while delivering the electric current in the corresponding circuit.
In the current field of preparing a silver-based electrical contact material, for example, in the preparation of a silver-carbon electrical contact material, generally silver powder and graphite powder are mixed homogenously by a dispersion method such as powder metallurgy or high energy ball milling, and then the mixed powder is subject to isostatic pressing sintering, extrusion moulding, slicing and other process steps, thereby obtaining the desired contact material. However, during the treatment of the powder, traditional methods of mixing powder, namely powder metallurgy and high energy ball milling, at most can achieve microscale homogenous mixing, and also often lead to inhomogeneous mixing accompanied with powder agglomeration and other phenomena. These factors seriously affect the mechanical and physical properties, electrical properties and other properties of the electrical contact material obtained by sintering the powder. In addition to the above reason that the powder metallurgy or high energy ball milling process tends to cause inhomogeneous powder agglomeration, the process also tends to cause contamination of an electrical contact material with a ball milling medium because of a relatively long treatment time.
In addition, in order to improve the overall performance of an electrical contact material, a carbonaceous material can be added to the electrical contact material. But, at present, it has been found that in such processes, the carbonaceous material exhibits both poor coating and poor invasion with respect to the atomized silver powder, thereby seriously affecting the performance of the silver-based electrical contact material.
Among the above methods comprising the addition of carbonaceous materials, there are attempts to directly add a diamond to a silver-based electrical contact material, with a view to improving the wear resistance of the electrical contact material and thus extending the service life of the material. Although a diamond can optimize the mechanical properties of a silver-based electrical contact material, it also greatly increases the production cost of the material, so such methods are not feasible in actual production. Moreover, it is difficult to achieve uniform dispersion by adding a diamond using a powder metallurgy method.
In order to solve the above problems, the inventors have conducted in-depth and meticulous researches, and have solved the above problems using the technical solution of the present invention.